Electric circuit for dimming vehicle lights



1965 JITSUO HANANO 3,201,643

ELECTRIC CIRCUIT FOR DIMMING VEHICLE LIGHTS Filed Dec. 16, 1959 PHOTO ELECTRIC, CELL POWER REL 4) POWER RIG 4 RELAY CELL a @7715 00 IL/ANANO, 7 l6 INVENTOR,

M BY 3,201,643 ELECTRIC CIRCUIT FOR DIMMING VEHICLE LIGHTS Jitsuo Hanano, 3 Z-chome, Ohilre-cho, Suma-ku, Kobe-ski, Hyogolreu, Japan Filed Dec. 16, 1959, Ser. No. 859,899 2 Claims. (Cl. SIS-83) This invention relates to an electric circuit for selecting the proper headlight beam of an automobile, a motorcycle or other vehicles when vehicles approach from the opposite direction.

There will be a danger of causing traffic accidents if drivers are blinded by a strong beam or an upper beam of the other car travelling in the opposite direction. To avoid accidents, drivers must actuate the switch of the headlight from upper to lower beam. But drivers do not always do this due to their inattention or negligence. To prevent accidents caused by such inattention, electric devices controlled by photosensitive means are used which automatically shift the headlight from upper to lower beam when other cars approach from the other direction and shift it back to the upper beam when the car has passed. 7

When such automatic devices are used, the shifts of the beams will occur too frequently when many cars approach successively, and then driving will become very difficult, due to the rapid and continual readjustments which the driver must make to the changing lighting conditions.

To overcome this difliculty, only the shift from upper to lower beam is automatically operated and the shift back to the upper beam is done manually in this invention.

An object of the invention is to provide an electric circuit which comprises a light sensitive plate such as a phototube or a photocell which releases an electric current, a power relay and switches which switch the high filament out of the circuit and switch the low filament into the circuit automatically but their reverse switching is done by hand.

More details and practical embodiments of the invention will be shown in the accompanying drawings in which:

FIG. 1 is a schematic diagram of an electric circuit showing its state in the daytime in which both beams are switched out.

FIG. 2 is a diagram showing a state in which a cur rent flows through only the high filament.

FIG. 3 is a diagram showing a state in which a current flows through only the low filament.

A top portion of a car is provided with a light sensitive device 2 which has a light sensitive plate 17 such as a photocell or a phototube. The light sensitive device 2 is connected to an electromagnet 13 through a power relay 3 and a battery 4 as a D.C. source to operate the magnet 13. The electromagnet 13, a switch blade 19, a spring 15 and a contact 8 form an electromagnetic switch. The contact 8, a high filament 5, a low filament 6 and a contact 11 are connected with each other in series. The switch blade 19, a contact 10, an electromagnet 14, a hand or foot switch 9, a battery 7, providing a current source for the filaments, and a switch 12 are connected in series with the high filament 5. The other side of the switch 12 is connected to both the high 5 and the low 6 filaments. A switch blade 18 provided with a spring 16 is mounted between the battery 7 and the switch 9. The switch blade 18 is thrown between the contacts 10 and 11 by forces of the spring 16 and the electromagnet 14. a

In the daytime as shown in FIG. 1, the switches 12, 9

United States Patent 0 3,261,643 Patented Aug. 17, 1965 and contact 10 are opened and the light sensitive plate is covered with a shield (not shown). Accordingly no current will flow in any of the circuits.

At night the circuit will be in the condition as shown in FIG. 2. First, the switches 12 and 9 are closed and a current flows from the battery 7 through the switch 9, the coil of the electromagnet 14, the switch blade 19, the contact 8, the high filament 5 and the switch 12. The shield on the light sensitive plate 17 is removed but light intensity at night is not enough to operate the light sensitive device and the power relay 3 remains opened. Accordingly the electromagnet 13 is not energized and the contact 8 remains closed. When a current flows through the coil of the electromagnet 14 the switch blade 18 will be thrown in the direction of the magnet 14 against the tension force of the spring 16, to open the contact 11 and to close the contact 10. In this state, even if the switch 9 is opened (as shown in FIG. 2) by removing the force to close it, a current flows through the contact 10 to light the upper beam of the headlight. The opening of the contact 11 will cause switching out of the low filament 6.

When a car approaches from the other direction and its headlight of high intensity strikes the light sensitive plate 17, as shown in FIG. 3, a current will be released to operate the power relay 3 and the circuit of the electromagnet 13 will be closed. The magnet 13 thus energized will throw the switch blade 19 in the direction of the magnet 13 against the force of the spring 15 and then the contact 8 will be opened. At this time, the circuit of the high filament 5 is opened, the strong headlight beam is switched out, the electromagnet 14 is deenergized, the switch blade 18 will be thrown against the contact 11 to close the circuit of the low filament and a weaker headlight beam will be switched in. When the car has passed, the light sensitive device 2 becomes inactive, the power relay 3 will be opened to cause deenergizing of the electromagnet 13 and the contact 8 will then be closed. If an operator does not close the switch 9 a current continues to flow through the low filament 6 and does not flow through the high filament 5. If he desires to shift the light from lower to upper beam, he must close the switch 9 by hand or foot. Once a current flows through the circuit of the high filament 5 by closing of the switch 9 the contact 11 will be opened and the contact 10 will be closed even if the switch 9 is opened, as shown in FIGURE 2.

Thus the circuit returns back to the state of FIG. 2 and is ready to operate for next approaching cars.

This invention will greatly serve for safety in trafl ic by its automatic shift from upper to lower beam to prevent accidents caused by a driver who fails to shift the headlight beams. Furthermore, even when many cars successively come in opposite direction too frequent shifts of the beams will not occur owing to providing a manipulative means to return back to the strong beam.

There could be a problem when two cars with different intensities of their headlight beam approach each other and only the weaker beam will shift and the stronger beam will remain strong. But such inconvenience does not occur owing to the existence of a time interval between the time of the light striking and the time the switching of beams actually occurs in this electric device. When such two cars approach each other, the car with a Weaker light approaches the other car during this time interval and is thus able to strike the light sensitive device of the car with a stronger light.

When a car enters a bright area such as a busy street the upper beam will continue to be switched out.

As mentioned above, this invention is very convenient for the operation of cars.

condition in which said high filament is disconnected from said source and said low filament is connected to said source when light of a predetermined intensity reaches said light sensitive means, and for retaining said circuit in this condition even after said light sensitive means What I claim is:

1. An electrical circuit device for use in vehicles and the like, comprising, in combination:

a source of electrical energy;

a high filament and a lowfilament;

circuit means, including manually actuable switch means, for connecting said filaments with said energy source and including filament control means including a light sensitive means ceases to detect light of the predetermined intensity, said filament control means including a first relay contact connected incircuit with for controlling said circuit into a condition in which said high filament and said source, an electrosaid high filament is disconnected from said source magnet connected to be operated by said light and said low filament is connected to said source sensitive means for controlling said first relay when light of a predetermined intensity reaches said contact and opening it when said light of a light sensitive means and for retaining said circuit predetermined inten ity is detected, and a device in this condition ever after said light sensitive means for biassing said two-position switch in said one ceases to detect light of the predetermined intensity, position;

said filament control means comprising first means, (2) manually actuable switch means counteractincluding an electromagnet, for holding said high ing the retaining action of said filament control filament connected to said source upon actuation of means for connecting said high filament with said manually actuatable switch means until disconsaid source; and

nection by said light sensitive means, a two position (3) means for holding said high filament conswitch for connecting said low filament with said nected to said source upon actuation of said source in one position and for connecting said high manually actuable switch means until disconfilament with said source when in the other posinection by said light sensitive means, said holdtion, and a device for biassing said two position ing means including an electromagnet for holdswitch toward said one position, said electromagnet ing, by magnetic attraction, said two-position being capable of holding the two position switch switch in said other position. in said other position by magnetic attraction. 2. An electrical circuit device for use in vehicles and I the like, comprising, in combination:

References Cited by the Examiner UNITED STATES PATENTS a a source of electrical ,ener 1 Eb a high filament and a low fi lament, I 1;694,51l 12/ 28 Llppe-Lipski 315-83.1 (c) circuit means for connecting said high and low Y jP T filaments with said energy source, said circuit means 2476382 6/49 Wan including a two-position switch for connecting said 2598420 5/5,) low filament w1th said source when in one position 749,478 6/56 Gandelot 315 83'1 and for connecting said high filament with said source when 1n the other position, sald circuit means GEORGE N. WESTBY, Primary Examiner. further including (1) filament control means, including light sensi- AR R G RALPH NILSON, Examinel'stive means, for controlling said circuit into a 

1. AN ELECTRICAL CIRCUIT DEVICE FOR USE IN VEHICLES AND THE LIKE, COMPRISING, IN COMBINATION: A SOURCE OF ELECTRICAL ENERGY; A HIGH FILAMENT AND A LOW FILAMENT; CIRCUIT MEANS, INCLUDING MANUALLY ACTUABLE SWITCH MEANS, FOR CONNECTING SAID FILAMENTS WITH SAID ENERGY SOURCE AND INCLUDING FILAMENT CONTROL MEANS INCLUDING A LIGHT SENSITIVE MEANS FOR CONTROLLING SAID CIRCUIT INTO A CONDITION IN WHICH SAID HIGH FILAMENT IS DISCONNECTED FROM SAID SOURCE AND SAID LOW FILAMENT IS CONNECTED TO SAID SOURCE WHEN LIGHT OF A PREDETERMINED INTENSITY REACHES SAID LIGHT SENSITIVE MEANS AND FOR RETAINING SAID CIRCUIT IN THIS CONDITION EVER AFTER SAID LIGHT SENSITIVE MEANS CEASES TO DETECT LIGHT OF THE PREDETERMINED INTENSITY, SAID FILAMENT CONTROL MEANS COMPRISING FIRST MEANS, INCLUDING AN ELECTROMAGNET, FOR HOLDING SAID HIGH FILAMENT CONNECTED TO SAID SOURCE UPON ACTUATION OF SAID MANUALLY ACTUATABLE SWITCH MEANS UNTIL DISCONNECTION BY SAID LIGHT SENSITIVE MEANS, A TWO POSITION SWITCH FOR CONNECTING SAID LOW FILAMENT WITH SAID SOURCE IN ONE POSITION AND FOR CONNECTION SAID HIGH FILAMENT WITH SAID SOURCE WHEN IN THE OTHER POSITION, AND A DEVICE FOR BIASSING SAID TWO POSITION SWITCH TOWARD SAID ONE POSITION, SAID ELECTROMAGNET BEING CAPABLE OF HOLDING THE TWO POSITION SWITCH IN SAID OTHER POSITION BY MAGNETIC ATTRACTION. 